Convolvulus verecundus f. glaberrimus
Synonyms
None - first described in 2019
Family
Convolvulaceae
Flora category
Vascular – Native
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Structural class
Herbs - Dicotyledons other than Composites
Interim conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2017 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes a statistical summary and brief notes on changes since 2012 and replaces all previous NZTCS lists for vascular plants.
Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – an interim threat classification status has not been assessed by the NZTCS panel.
- Conservation status of New Zealand indigenous vascular plants, 2017 . 2018. Peter J. de Lange, Jeremy R. Rolfe, John W. Barkla, Shannel P. Courtney, Paul D. Champion, Leon R. Perrie, Sarah M. Beadel, Kerry A. Ford, Ilse Breitwieser, Ines Schönberger, Rowan Hindmarsh-Walls, Peter B. Heenan and Kate Ladley. Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2019 | Threatened – Nationally Critical | Interim
Brief description
Scrambling plant allied to Convolvulus verecundus f. verecundus from which it differs by the brown-green, glabrous to glabrate leaves, with prominent and strongly translucent veins, and undulating to occasionally sinuate leaf margins.
Distribution
Endemic. South Island, North Otago, Awahokomo.
Habitat
Limestone endemic. Known from one location where it grows on ledges, cracks and crevices infilled with limestone fragments, and on shallow skeletal rendzina and colluvium.
Detailed description
Low-growing perennial herb, with creeping rhizomatous stems, short ascending to spreading branches, and lianoid stems up to 200 mm; lianoid stems with a sparse to moderate covering of retrorse hairs. Leaves in rosettes and alternate on stems, 6.5–12.0 × 4.0–8.0 mm, deltoid, deltoid-ovate to ± broad-oblong, brown-green, glabrous to glabrate; veins prominent and strongly translucent; margin undulate, occasionally sinuate; base truncate, obtuse, occasionally oblique or slightly cordate; apex usually retuse or obtuse; petiole channelled, glabrous to glabrate. Pedicel 5–30(–55) mm long, 0.4–1.2 mm diam., moderately hairy. Sepals 3.9–4.1 × 3.5–3.8 mm, obovate to ovate, green; abaxial surface sparsely to moderately hairy, adaxial surface glabrous; margin fimbriate and translucent; apex subacute to obtuse. Corolla 12–19 mm long in bud, 20–25 mm wide when open, white, rarely pink, five lobes fused their full length, lobe apex fringed with hairs; tube 5–8 mm long, pale green; abaxial surface with midline of petal with pink bands with sparse appressed hairs on upper half. Nectary annular, 0.3–0.4 mm tall, yellow. Style 2-cleft, white; fused portion 6.0–9.0 mm long, c. 0.2 mm wide; stigmata 2.5–4.0 × c. 0.5 mm. Ovary c. 1.0 × 1.0–1.2 mm, cream. Filaments 4.0–4.6 mm long, c. 0.5 mm wide at base, tapering to c. 0.2 mm at apex, white; margin with scattered short hairs on lower half; fused to base of corolla tube. Anthers 1.7–2.0 mm long, white. Capsule 5.8–6.2 mm long, 4.5–7.5 mm wide, chartaceous, globose, with 2–4 seeds, lower half enclosed in persistent calyx, style base remnant persistent. Seeds segment-shaped and broader toward apex with a rounded dorsal and two flattened lateral faces meeting at an acute ventral edge, or rounded and broadly obovate without distinct angles, almost triangular to terete in section; 2.8–3.9 × 2.4–3.0 mm; apex and base rounded; hilum concave. Testa black-brown overlaid and ornamented with grey nut-brown, dull, glabrous, moderately covered in low ridges and tubercules, sometimes forming ridges on margins
Similar taxa
Most similar to Convolvulus verecundus f. verecundus from which it differs by the brown-green, glabrous to glabrate leaves, with prominent and strongly translucent veins, and by the undulating to occasionally sinuate leaf margins.
Flowering
November - January
Flower colours
White
Fruiting
December - March
Propagation technique
Not known from cultivation.
Threats
Convolvulus verecundus f. glaberrimus occupies an area of about 12 square metres where there are an estimated 15 plants. Therefore, Heenan & Molloy (2019) recommended that it be assessed as ‘Threatened-Nationally Critical’ (Criterion “A” of very small population (natural or unnatural). They note that two of the ‘Nationally Critical’ A subcriteria also apply: A(1) < 250 mature individuals and A(3) total area of occupancy ≤ 1 hectare (see Townsend et al. 2008)). Heenan & Molloy (2019) considered that the qualifier ‘DP’ (data poor) and ‘OL’ (one location) apply. This is because there is no population trend data, and the race is known from only one location.
Etymology
convolvulus: From Latin convolvere, which means to twine around
glaberrimus: From ‘glaber’ (hairless) and ‘rimus’ (to the greatest degree) i.e. ‘extremely hairless’
Attribution
Fact sheet prepared by P.J. de Lange (5 September 2019). Description from Heenan & Molloy (2019).
References and further reading
Heenan, P.B.; Molloy, B.P.J. 2019: Five new and Nationally Threatened taxa of Brachyscome, Cardamine, Convolvulus, Geranium and Ranunculus obligate to vulnerable limestone habitats, eastern South Island, New Zealand. Phytotaxa 415(1): 32-48.
Townsend, A.J., de Lange, P.J., Norton, D.A., Molloy, J., Miskelly, C.; Duffy, C. 2008: The New Zealand Threat Classification System manual. Department of Conservation, Wellington, 35 pp.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Convolvulus verecundus f. glaberrimus Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/convolvulus-verecundus-f-glaberrimus/ (Date website was queried)